Structure of the Human Kidney: Cortex, Medulla and Pelvis
Biology · Excretory Products and Their Elimination · NEET
A human kidney has an outer part called the cortex and an inner part called the medulla. The medulla is divided into cone-shaped renal pyramids (medullary pyramids); the cortex dips between these pyramids as the columns of Bertini. Urine drains from the pyramid tips into cup-shaped calyces, then into the funnel-shaped renal pelvis, which leads to the ureter. Memory hook: outside CORTEX, inside MEDULLA, and the PELVIS is the drain.
Longitudinal section of a human kidney: the outer cortex, the inner medulla with cone-shaped pyramids, cortical columns of Bertini dipping between pyramids, and the funnel-shaped pelvis draining into the ureter.
Your doubts, answered
Is the cortex the outer part or the inner part of the kidney?
The cortex is the OUTER part of the kidney, lying just under the capsule. The medulla is the INNER part. Students often flip these two. Simple trick: 'cortex' sounds like 'cover', so it is on the outside covering the medulla.
What is the difference between the renal medulla and the renal pelvis?
The medulla is solid kidney TISSUE (the inner zone with the pyramids). The renal pelvis is a HOLLOW SPACE, a funnel that collects urine before it goes into the ureter. So medulla = tissue, pelvis = collecting funnel. They are not the same thing.
What are the columns of Bertini?
The columns of Bertini (renal columns) are extensions of the cortex tissue that go DOWN between the medullary pyramids. So the cortex is not only the outer layer; part of it dips inward as these columns. NEET has asked about them directly, so remember: columns of Bertini are cortical tissue, not medullary.
Where does the notch (hilum) sit and what passes through it?
The hilum is a notch on the inner (concave) side of the kidney. Through the hilum pass the ureter, the blood vessels (renal artery and vein), and nerves. Inside the hilum lies the renal pelvis, into which the calyces open.
How does urine travel from the pyramids to the ureter?
Urine leaves the tips (renal papillae) of the medullary pyramids, drips into small cup-shaped calyces, the calyces open into the renal pelvis (a big funnel), and the pelvis narrows into the ureter. Order to remember: pyramid tip → calyx → pelvis → ureter.
⚠️ The NEET trap ✗ The columns of Bertini and the renal pyramids are both parts of the medulla. ✓ The renal pyramids are part of the medulla, but the columns of Bertini are extensions of the CORTEX that project inward between the pyramids. 🧠 Bertini = Cortex Between pyramids. If a question calls the columns of Bertini 'medullary', it is wrong.
Real NEET questions
2024
Choose the correct statement given below regarding juxta medullary nephron.
A · Renal corpuscle of juxta medullary nephron lies in the outer portion of the renal medulla.
B · Loop of Henle of juxta medullary nephron runs deep into medulla. ✓
C · Juxta medullary nephrons outnumber the cortical nephrons.
D · Juxta medullary nephrons are located in the columns of Bertini.
Solution: The loop of Henle of a juxta medullary nephron is very long and runs deep into the medulla, so B is correct. The other options test kidney structure: the renal corpuscle lies in the cortex (not the medulla), cortical nephrons outnumber juxta medullary ones, and the columns of Bertini are cortical extensions between the medullary pyramids, not where these nephrons sit.
Solved Excretory Products and Their Elimination NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
What are the two main regions of the human kidney?
The outer cortex and the inner medulla. The medulla is further divided into conical renal (medullary) pyramids.
What are renal pyramids?
Renal pyramids, also called medullary pyramids, are cone-shaped masses of tissue in the medulla. Their tips (papillae) point toward the pelvis and drain urine into the calyces.
What is the renal pelvis?
The renal pelvis is a broad, funnel-shaped hollow space inside the kidney. It collects urine from the calyces and passes it into the ureter.
Why do the columns of Bertini matter for NEET?
Because NEET repeatedly tests whether students know they are cortical tissue (extensions of the cortex) sitting between medullary pyramids, a common trap where students wrongly call them medullary.
What passes through the hilum of the kidney?
The ureter, the renal blood vessels (renal artery and renal vein) and nerves pass through the hilum, a notch on the inner concave border of the kidney.
